/********************************************************************************
 * Copyright (c) 2011-2017 Red Hat Inc. and/or its affiliates and others
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License 1.0 which is available at
 * http://www.eclipse.org/legal/epl-v10.html.
 *
 * SPDX-License-Identifier: EPL-1.0
 ********************************************************************************/
package org.eclipse.ceylon.ide.eclipse.code.explorer;

import org.eclipse.core.resources.IContainer;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.jdt.core.IJavaElement;
import org.eclipse.jdt.core.IJavaModel;
import org.eclipse.jdt.core.JavaCore;
import org.eclipse.jdt.internal.ui.IJavaHelpContextIds;
import org.eclipse.jdt.internal.ui.packageview.PackagesMessages;
import org.eclipse.jface.action.Action;
import org.eclipse.jface.viewers.StructuredSelection;
import org.eclipse.jface.viewers.StructuredViewer;
import org.eclipse.jface.viewers.TreeViewer;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.dialogs.FilteredResourcesSelectionDialog;

class GotoResourceAction extends Action {

    private PackageExplorerPart fPackageExplorer;

    private static class GotoResourceDialog extends FilteredResourcesSelectionDialog {
        private IJavaModel fJavaModel;
        public GotoResourceDialog(Shell parentShell, IContainer container, StructuredViewer viewer) {
            super(parentShell, false, container, IResource.FILE | IResource.FOLDER | IResource.PROJECT);
            fJavaModel= JavaCore.create(ResourcesPlugin.getWorkspace().getRoot());
            setTitle(PackagesMessages.GotoResource_dialog_title);
            PlatformUI.getWorkbench().getHelpSystem().setHelp(parentShell, IJavaHelpContextIds.GOTO_RESOURCE_DIALOG);
        }

        @Override
        protected ItemsFilter createFilter() {
            return new GotoResourceFilter();
        }

        private class GotoResourceFilter extends ResourceFilter {

            /*
             * (non-Javadoc)
             *
             * @see org.eclipse.ui.dialogs.FilteredResourcesSelectionDialog.ResourceFilter#matchItem(java.lang.Object)
             */
            @Override
            public boolean matchItem(Object item) {
                IResource resource = (IResource) item;
                return super.matchItem(item) && select(resource);
            }

            /**
             * This is the orignal <code>select</code> method. Since
             * <code>GotoResourceDialog</code> needs to extend
             * <code>FilteredResourcesSelectionDialog</code> result of this
             * method must be combined with the <code>matchItem</code> method
             * from super class (<code>ResourceFilter</code>).
             *
             * @param resource
             *            A resource
             * @return <code>true</code> if item matches against given
             *         conditions <code>false</code> otherwise
             */
            private boolean select(IResource resource) {
                IProject project= resource.getProject();
                try {
                    if (project.getNature(JavaCore.NATURE_ID) != null)
                        return fJavaModel.contains(resource);
                } catch (CoreException e) {
                    // do nothing. Consider resource;
                }
                return true;
            }

            /*
             * (non-Javadoc)
             *
             * @see org.eclipse.ui.dialogs.FilteredResourcesSelectionDialog.ResourceFilter#equalsFilter(org.eclipse.ui.dialogs.FilteredItemsSelectionDialog.ItemsFilter)
             */
            @Override
            public boolean equalsFilter(ItemsFilter filter) {
                if (!super.equalsFilter(filter)) {
                    return false;
                }
                if (!(filter instanceof GotoResourceFilter)) {
                    return false;
                }
                return true;
            }
        }

    }

    public GotoResourceAction(PackageExplorerPart explorer) {
        setText(PackagesMessages.GotoResource_action_label);
        PlatformUI.getWorkbench().getHelpSystem().setHelp(this, IJavaHelpContextIds.GOTO_RESOURCE_ACTION);
        fPackageExplorer= explorer;
    }

    @Override
    public void run() {
        TreeViewer viewer= fPackageExplorer.getTreeViewer();
        GotoResourceDialog dialog= new GotoResourceDialog(fPackageExplorer.getSite().getShell(),
            ResourcesPlugin.getWorkspace().getRoot(), viewer);
         dialog.open();
         Object[] result = dialog.getResult();
         if (result == null || result.length == 0 || !(result[0] instanceof IResource))
             return;
         StructuredSelection selection= null;
        IJavaElement element = JavaCore.create((IResource)result[0]);
        if (element != null && element.exists())
            selection= new StructuredSelection(element);
        else
            selection= new StructuredSelection(result[0]);
        viewer.setSelection(selection, true);
    }
}